| Construct | Item |
| Green purchasing (Zhu et al., 2008a) | Eco labeling of products. |
| Cooperation with suppliers for environmental objectives. | |
| Environmental audit of suppliers’ internal management. | |
| Second-tier supplier environmentally friendly practice evaluation. | |
| Eco-design (Zhu et al., 2008a) | Design of products for reduced consumption of material/energy. |
| Design of products for reuse, recycle, recovery of material and/or component parts. | |
| Design of products to avoid or reduce use of hazardous products and/or their manufacturing process. | |
| SMEs performance (Sadiku-dushi et al., 2019) | My firm is usually satisfied with sale growth. |
| My firm is usually satisfied with market share growth. | |
| My firm is usually satisfied with return on sales. | |
| My firm is usually satisfied with net profit margins. | |
| My firm is usually satisfied with gross profit margins. | |
| Environmental performance (Zhu et al., 2008a) | Reduction of air emissions. |
| Reduction of effluent waste. | |
| Reduction of solid wastes. | |
| Decrease in consumption for hazardous/harmful/toxic materials. | |
| Decrease in frequency for environmental accidents. |